package com.mpsc.singleton.demo.advice;


import com.fasterxml.jackson.core.JsonProcessingException;
import com.fasterxml.jackson.databind.ObjectMapper;
import com.mpsc.singleton.demo.common.BaseResponse;
import org.springframework.core.MethodParameter;
import org.springframework.http.MediaType;
import org.springframework.http.converter.HttpMessageConverter;
import org.springframework.http.server.ServerHttpRequest;
import org.springframework.http.server.ServerHttpResponse;
import org.springframework.web.bind.annotation.RestControllerAdvice;
import org.springframework.web.servlet.mvc.method.annotation.ResponseBodyAdvice;

@RestControllerAdvice(basePackages = "com.mpsc.spring.demo")
public class ResponseAdvice implements ResponseBodyAdvice<Object> {

    @Override
    public boolean supports(MethodParameter returnType, Class<? extends HttpMessageConverter<?>> converterType) {
        // 如果不需要进行封装的，可以添加一些校验手段，比如添加标记排除的注解
        return true;
    }


    @Override
    public Object beforeBodyWrite(Object body, MethodParameter returnType, MediaType selectedContentType, Class<? extends HttpMessageConverter<?>> selectedConverterType, ServerHttpRequest request, ServerHttpResponse response) {
        // 提供一定的灵活度，如果body已经被包装了，就不进行包装
        if (body instanceof BaseResponse) {
            return body;
        }

        if (body instanceof String) {
            try {
                return new ObjectMapper().writeValueAsString(new BaseResponse(200, body));
            } catch (JsonProcessingException e) {
                e.printStackTrace();
            }
        }
        return new BaseResponse(200, body);
    }
}
